Cytochrome bd oxidase, oxidative stress, and dioxygen tolerance of the strictly anaerobic bacterium Moorella thermoacetica.

ABSTRACT: The gram-positive, thermophilic, acetogenic bacterium Moorella thermoacetica can reduce CO2 to acetate via the Wood-Ljungdahl (acetyl coenzyme A synthesis) pathway. This report demonstrates that, despite its classification as a strict anaerobe, M. thermoacetica contains a membrane-bound cytochrome bd oxidase that can catalyze reduction of low levels of dioxygen. Whole-cell suspensions of M. thermoacetica had significant endogenous O2 uptake activity, and this activity was increased in the presence of methanol or CO, which are substrates in the Wood-Ljungdahl pathway. Cyanide and azide strongly (approximately 70%) inhibited both the endogenous and CO/methanol-dependent O2 uptake. UV-visible light absorption and electron paramagnetic resonance spectra of n-dodecyl-beta-maltoside extracts of

SUBMITTER: Das A 

PROVIDER: S-EPMC1064043 | biostudies-literature | 2005 Mar

REPOSITORIES: biostudies-literature